1st gen rapidfire and rapidfire plus did not have indicators and nobody cared. Then they came out with windows under the bars. These are now hard to run on riser bars so they went over the bars.
Usually one knows which chainring they are in, even on a triple. Once you know that, its pretty easy to know where you are in the rear. Plus, I got used to looking down and back. Its not a big deal. I rarely do it but I do
The higher end gear allows you to remove the OGD, which makes space on the handlebar. For example, here I removed the OGD to allow the lock-out to be better placed. The OGD would have put it far away.
I dont like OGDs and remove them if I can. They serve me no purpose, are fragile, and look silly
They also lead to "bad gearing knowledge" as people start referring to their "1-6" gear; which means nothing to bike people, especially since even Shimano uses "1" for the low gear on some models and "3" on others for the same gear